Structure of natural product-ursolic acid was modified for increasing its antitumor activity. Ursolic acid was acylated, esterified, hydrolized or oxidized to obtain target pentacyclic triterpenoid compounds with different substitutes. Sixteen derivatives of ursolic acid were designed and synthesized including eleven new compounds. Anti-tumor activities of ursolic acid and these derivatives against HeLa, SKOV3 and BGC-823 cells in vitro were investigated by MTT assay. The results indicated that compounds 7a and 8a were found to have stronger cell growth inhibitory than ursolic acid on HeLa cells and SKOV3 cells separately, and are worth to be intensively studied further.

Objective:To investigate the effects of the "TECK" (theoretical class, experimental course, case discussion, and knowledge reinforcement) teaching model oriented by post competency in clinical pathology internship teaching.Methods:The intern students from 2015 to 2019 in the pathology direction of clinical medicine in the School of Pathology, Qiqihar Medical College, who were enrolled in the internship from 2019 to 2023, were selected as the research objects.We enrolled 32 medical students from grades 2017, 2018, and 2019 (research group) and 24 medical students from grades 2015 and 2016 (control group) who would participate in pathology internships. The control group adopted the traditional internship mode, while the research group adopted the competency-oriented "TECK" teaching mode. After the internship, the two groups were compared for internship assessment score and surveyed for post competency. With the use of SPSS 18.0 statistical software. Continuous data were presented as (mean±standard deviation) and t-test was used for comparison between groups. Count data were expressed in the number of cases, and chi-square test was used for comparison between groups.The significance level α was 0.05. Results:The research group showed significantly higher scores of skill assessment (82.81±4.20 vs. 79.58±5.09) and pathological diagnosis assessment (80.28±4.23 vs. 76.21±4.58) than the control group (both P<0.05), with no significant difference in the score of theoretical knowledge ( P>0.05). In terms of post competency, the research group was superior to the control group in clinical skills and medical care ability (12.38±0.94 vs. 11.35±0.76), disease prevention and health promotion ability (6.28±0.92 vs. 4.48±0.93), interpersonal communication and information management ability (19.81±1.09 vs. 17.00±1.28), and teamwork and scientific research ability (11.44±1.27 vs. 9.25±0.87; all P<0.05). There were no significant differences between the two groups in core values and professional literacy and medical knowledge and lifelong learning (both P>0.05). Conclusions:In undergraduate internships, the competency-oriented "TECK"teaching mode can significantly improve students' clinical operation and pathological diagnosis ability, and effectively cultivate their abilities of clinical skills and medical care, disease prevention and health promotion, interpersonal communication and information management, teamwork and scientific research.